Radiation detection device

ABSTRACT

The invention relates to a device for detecting input radiation such as X-rays, γ-rays, ionizing radiation or fluorescent and low-level light. The device has at least one detection element comprising a sensor component (scintillator) for converting the input radiation into photons (scintillation light) in the UV, visible or IR part of the electromagnetic spectrum and an optical amplifier component which receives the light converted by the sensor component, forwards it for further processing and amplifies it at the same time. According to the invention, the amplifier component comprises at least one optical waveguide ( 1, 2, 2   a,    2   b,    20 ) whose material is optically pumped to amplify the scintillation light ( 3, 24, 25 ).

The invention relates to a device for the detection of incidentradiation, e.g. X-rays, γ-rays, ionizing radiation and fluorescence orlow-level light, having at least one detecting element which has asensor section (scintillator, wavelength shifter, and the like) forconverting the incident radiation into photons in the UV, visible, or IRportions of the electromagnetic spectrum (e.g., scintillation light) andan optical amplifier section that receives the converted light from thedetector section, transmits it for further processing, and amplifies itin the process.

Devices and detectors for detection of incident radiation from thewavelength spectrum of X-rays and γ-rays are known in many embodiments.These devices have achieved great importance in the field of medicine,particularly in connection with imaging processes such as PET (positronemission tomography), SPECT (single photon emission computedtomography), scintigraphy (Anger camera), and X-ray CT (computedtomography).

Among the various imaging processes in medicine, MR (magnetic resonanceor nuclear magnetic resonance) tomography has great diagnosticimportance based on superior image quality and three-dimensional imageinformation. This is based on the measurement of the three-dimensionaldistribution of hydrogen atoms. It is orders of magnitude better thanother radiation or nuclear medicine processes such as scintigraphy andPET in terms of resolution. For these reasons MR tomography isparticularly suitable for diagnostic localization. In contrast, thestrengths of scintigraphy or PET are in the areas of detection ofphysiological parameters.

There thus exists a need for a medical instrument that appropriatelycombines the advantages of imaging processes based on physiologicalparameters, e.g. scintigraphy/PET, with those of imaging processes basedon structural information, as for example MR tomography.

Attempts to combine information from the two systems after the fact havebeen made at the Deutsche Krebsforschungszentrum [German Cancer ResearchCenter] among other places (L. R. Schad, “Three Dimensional ImageCorrelation of CT, MR and PET: Studies in Radiotherapy TreatmentPlanning of Brain Tumors”, Journal of Computer assisted Tomography,1987, II (6), p. 948-954).

However, a difficulty in the later combination of information frommultiple different imaging systems is that the human body is not rigid.Conversion problems thus arise among the various imaging systems.Attempts are made to compensate for these problems through digital imageprocessing, an effort which succeeds for tumors in the cranial regionthrough stereotactic methods.

A combination device that permits the simultaneous acquisition ofstructural information and the three-dimensional distribution ofradioactivity would be desirable. This is not achievable through acombination of currently available devices. The primary obstacles inthis regard are the high static magnetic field, the time-switched strongmagnetic field gradients, the pulsed incident electromagnetic waves inthe MHz region and the scarcity of available space for additionaldetection devices in the central area of an MR tomograph. For thisreason, electronic detectors cannot be used inside an MR tomograph. Thismeans that the crystals currently used in PET devices (BGO, BaF₂ and thelike) that are directly coupled to a photomultiplier are unsuitable forthe desired combination device.

These problems can be at least partially overcome by the use of bundlesof scintillating optical waveguides instead of crystals. Initial testsof bundled scintillating optical waveguides have already been published(R. C. Chaney et al, “Testing the Spatial Resolution and Efficiency ofScintillating Fiber PET Modules”, IEEE Transactions of Nuclear Science,Vol. 39 No. 5, October 1992). In a seminar presentation given at theGerman Cancer Research Center in the summer of 1995, Professor P. P.Antich reported on the first tests of a combination device (PET/MRtomography). Scintillating plastic optical waveguides were used in theseinstruments. The scintillation light exiting the end of the fiber bundlewas converted into an electrical signal with photomultipliers (thedistance between the scintillation light and photomultiplier wasapproximately 5 m here). In these experiments, great problems werepresented by the not to be neglected optical attenuation of thescintillating plastic fibers as well as the small number of photonsgenerated in the scintillating optical waveguides. The invention solvesprecisely these problems in an elegant fashion, as is described indetail below.

As an alternative to photomultipliers, MCPs (multichannel plates,multichannel plate amplifiers) are used to detect weak optical signals.A disadvantage of both systems is that high voltages in the range ofseveral hundred volts are required for their operation. This increasesthe cost of devices equipped with such detectors.

Electronic components are also used for detection of X-rays andγ-quanta. These are primarily PIN and avalanche diodes, which exhibit apronounced thermal noise characteristic and for this reason alone areinherently inferior to optical amplifiers.

Optical amplifiers are inherently superior to electronic amplifiers forphysical reasons because they have a better signal-to-noise ratio.

In summary, it can be said with regard to the above-described state ofthe art that the amplifier sections of known radiation detectors areonly conditionally suited for amplifying very weak signals andtransmitting these signals over large distances. A further disadvantageof the known devices is that very weak scintillation or fluorescencelight is only detectable with difficulty, especially in hard-to-reachexperimental or investigative arrangements. Moreover, a spatialseparation between the place of detection and the place of analysis isachievable only with difficulty on account of the weak signals.

Reference is made to the following publications regarding the generalstate of the art:

DE-OS 23 51 450; this publication relates to a scintigraphic collimatorthat serves to focus the γ-rays emerging from a γ-ray-emittingexperimental object.

DE-OS 24 46 226; this publication relates to a scintillator thatconsists of metal-ion-doped alkali halogenide material.

DE 39 18 843; this publication relates to an X-ray detector thatconsists of a series of small rods of scintillator material.

DE 33 27 031 A1; this publication relates to an X-ray device in which aslot-shaped X-ray image is converted into a visible image and deliveredvia an optical waveguide arrangement to an image intensifier whoseoutput image is translated into an electrical signal by a converter.

DE 43 34 594; this publication relates to a detector for high-energyradiation for computer tomography, wherein is provided a series ofscintillators which are associated with corresponding optical waveguidesthat are separated from one another by slits.

EP 0 471 926 A2; this publication relates to a fast, radiation-stableCT-scintillation system in which a special garnet material is used.

The objective of the present invention is to create a radiation detectorwhich can be used for imaging processes that have high spatialresolution even for weak incident radiation and especially incombination with difficult-to-reach arrangements.

Advantageous further refinements of the invention are presented in thesubsidiary claims. Advantageous applications of the device in accordancewith the invention are named in the application claims.

Thus in other words, the invention creates a radiation detector with adetecting element whose amplifier section ensures optical amplificationof scintillation light in the manner of a laser by means of an opticalwaveguide whose material is optically pumped. Through the opticalpumping, the photons obtained by the sensor section from the incidentradiation are amplified several thousand times. A crucial advantage ofthe device in accordance with the invention is that the opticalwaveguide, and thus the amplifier section, can be located in theimmediate vicinity of the photon generating location or also in thevicinity of an optical guide that conveys these photons to the amplifiersection. While even the weakest incident radiation or incident radiationin difficult-to-reach arrangements can be detected in the first case,where the optical waveguide is located in the immediate vicinity of thephoton generation point, the primary advantage of the second case wherethe pumped optical waveguide is located distant from the photongeneration point is that the photon amplification can take placeundisturbed by interfering fields such as large magnetic fields.

Of special importance for the invention is the fact that an opticalamplification takes place directly at the point of interaction ofgenerated photons or if necessary through intermediate stages. Thismakes it possible to detect very small numbers of photons. The detectorelement thus provides a very compact, directional, high-efficiencycomponent that additionally makes it possible to transmit informationover long distances and to obtain the energy needed for amplification(pumping light in purely optical form) over long distances as well. Inthis way there is a spatial and functional division among the sectionsresponsible for the conversion (e.g.,γ-quantum→ν-photon→amplification→transmission→electrical signal).

The sensor section and optical amplifier section each operate withoutelectronic components. That is to say, (electrical) energy is suppliednot through wires, but purely optically, which is a decisive advantageover existing silicon-based γ- and X-ray detectors. Thus, distances ofseveral meters to hundreds of meters can separate the peripherallylocated electronic assemblies, e.g. the readout section (for example aCCD camera with a computer interface), the pumping light source (forexample a laser diode that is required for generating the populationinversion in the optical amplifier section) on the one side, from thepurely optical section on the other side with the sensor sectionresponsible for conversion of the X-ray or γ-quanta and the opticalamplifier section.

The special optical waveguides required for the invention are alreadyavailable and/or can be manufactured to customer requirements (Le Verrefluore). Preferred in this context are heavy metal fluoride glasses(HMFG, halide glasses), where they are doped with atoms from thelanthanide group of the Periodic Table (rare earth metals or rareearths). The lanthanide group includes: cerium (Ce), praseodymium (Pr),neodymium (Ne) [sic], promethium (Pm), samarium (Sm), europium (Eu),gadolinium (Ga) [sic], terbium (Tb), dysprosium (Dy), holmium (Ho),erbium (Er), thulium (Tm), ytterbium (Yb) and lutetium (Lu). Proof oflaser activity has been demonstrated for the following rare earth metalsin heavy metal fluoride glasses (status as of 1991; source: FluorideGlass Fiber Optics, Ishar D. Aggarwal, Gand Lu, Academic Press, Inc.,1991): Nd, Er, Ho, Tm. In the meantime, laser activity has beendemonstrated for nearly all rare earth metals. Additional preferredoptical waveguides include glass ceramic material, chalcogenide glassesand phosphate glasses.

The above-mentioned glasses, particularly the heavy metal fluorideglasses, are multiple component glasses.

One of the advantages over doped silicate glasses is that significantlyhigher doping concentrations can be achieved with rare earth metals,which results in higher efficiency for optical amplifiers and fiberlasers.

A further advantage of heavy metal fluoride glasses doped with rareearth metals is that this material, unlike conventional silicate glassoptical waveguides, exhibits crystal-like characteristics. Heavy metalfluoride glasses consist of materials such as BaF₂, CeF, for example,that are already used in crystalline form as radiation detectors. It isadvantageous that heavy metal fluoride glasses have a high density thatis sufficient to achieve the necessary stopping power (dE/dx; energyloss E per distance x) for γ-rays. This stopping power is not achievablewith the plastic fibers that are common to date in this area and inhigh-energy physics. A further advantage arising from the use of heavymetal fluoride glass as an optical waveguide is that these opticalwaveguides can themselves function as collimators. An advantage of theheavy metal fluoride glasses over crystals for radiation detectionresides in their simple handling, their easy workability, and theirinexpensive manufacture.

In accordance with an advantageous refinement of the invention, directpopulation inversion through light at the pump wavelength λ₁ is notused; rather, a physical up-conversion process, or a variant thereofknown as avalanche conversion is used. The long fluorescence lifetime ofrare earth ions in heavy metal fluoride glasses benefits opticalfrequency up-conversion. In this process, a rare earth ion is firstraised to a long-lived intermediate excitation state, from which itreaches a still higher state in a second step.

The pumped optical waveguide used in accordance with the invention foramplification of the scintillation light can take many forms. Theoptical waveguide is advantageously formed as an optical fiber, which ispreferably enclosed by a jacket in a manner known per se. Injection ofthe pump light into the fiber is done either directly into the core ofthe fiber or into the inner region of the fiber jacket. The fiber jacketpreferably consists of scintillating material and thereby forms thesensor part of the detection device.

In accordance with an advantageous refinement of the invention, pulsedpumping light can be used in addition to continuous pumping light sothat the optical amplifier can be time-triggered or activated. By thismeans, coordinated processes can be better observed. An application incardiac scintigraphy (myocardial scintigraphy) may be considered anexample of this. Thus the optical amplifier can be switched on atcertain phases of heart action through simultaneous derivation from theelectrocardiogram, where the switch-on phases can reach the picosecondrange. This technique can be used for compensation of movement artifactsthat are caused by breathing or circulation, for example.

In addition to single images, time series can also be detected byperiodic pulsed activation. This is advantageous for kineticinvestigation of heart function and, for example, for imaging of scartissue after myocardial infarction.

The optical waveguide provided in accordance with the invention can alsotake the form of a columnar microstructure, that is grown, for example,on a silicon wafer. In addition to the columnar form, other forms forthe microstructure elements that are suitable for the particularapplication purpose may be considered. Planar waveguides are likewisesuitable for special applications.

As explained above, photon-emitting substances in the optical waveguidethat come into consideration include rare earth metals, for instance. Asan alternative, dye molecules can be used as the dopant.

A preferred area of application for the device in accordance with theinvention lies in the area of radioimmunoassays, in which β-radiation isevaluated. β-Radiation has only a very short range. Active amplifierelements on the basis of the pumped optical waveguide in accordance withthe invention, for instance in the form of fiber bundles or in the formof columnar microstructures on a silicon wafer (or a gallium arsenidesubstrate on which laser diodes and photodiodes for detection areimplemented together) can serve in this application asmicro-scintillators and micro-amplifiers of scintillation light producedby β-radiation. A special advantage of this application is that theseelements can serve as a substitute for normal filler material. A veryhigh resolution capability in the detection of β-radiation is achievablethrough an arrangement of this nature. Also of advantage is thereusability of the arrangement, as well as its convenient use, since theevaluation can proceed in a manner similar to that for film material.

An additional preferred application of the device in accordance with theinvention lies in the area of biosensors. As an example an applicationfrom the field of molecular biology where fluorescence light is to beamplified will be described briefly here. In this process, antibodiesare coupled to a light-amplifying fiber or a planar waveguide oflight-amplifying material in accordance with the present invention. Forthis purpose a part of the outer jacket or the outer layer of thewaveguide is preferably made porous by etching. The antigen is loadedwith a fluorescence molecule. A part of the fluorescence light of asingle dye molecule excited from inside or outside penetrates the activestructure element (the light-amplifying fiber or the active planarwaveguide) and is locally amplified there. The locally amplifiedfluorescence light can then be transmitted without loss to a spatiallydistant evaluation system. The particular advantage of this arrangementis that the location of amplification can be selected to be distant fromthe location of evaluation.

In summary, the present invention offers advantages including thefollowing:

Even the weakest signals can be acquired and transmitted over largedistances if necessary by means of the amplification in accordance withthe invention.

Even very weak scintillation or fluorescence light can be detected inarrangements that are inaccessible or only accessible with difficultyusing conventional detectors.

Incident radiation can be locally detected, amplified, and transmittedto a distant evaluation system, for example a CCD camera.

It is possible to achieve the physical separation of the point ofconversion from γ- or X-ray quanta into light quanta with simultaneousamplification by optical pumping as well as by later conversion of theoptical signal into an electrical signal.

The radiation detection device in accordance with the invention can bemanufactured inexpensively.

The invention is described in greater exemplary detail below with theaid of the drawing; shown in:

FIG. 1 is a schematic representation of a first embodiment of thedetecting unit of the radiation detection device in accordance with theinvention;

FIG. 2 is a second embodiment of the detecting unit of the radiationdetection device in accordance with the invention;

FIG. 3 is a third embodiment of the detecting unit of the radiationdetection device in accordance with the invention;

FIG. 4 is a fourth embodiment of the detecting unit of the radiationdetection device in accordance with the invention;

FIG. 5 is a special application of the detecting unit of the radiationdetection device in accordance with the invention for detection ofγ-radiation; and

FIG. 6 is a special application of the detecting unit of the radiationdetection device in accordance with the invention as a fluorescencesensor.

All detecting units shown in the drawing have integrated construction ofsensor section and amplifier section.

FIG. 1 shows a first embodiment of the detecting element of the devicefor detecting incident radiation in accordance with the invention. Thedetecting element is an optical fiber amplifier consisting of a fibercore 1 and a jacket (cladding) 2 that surrounds the fiber core. The core1 forms the amplifying section and consists of an optically activematerial that is optically pumped as shown by an arrow 3 which indicatesthe direction of injection of pumping light. The jacket 2 consists of ascintillating material which has a lower optical index of refractionthan the fiber core 1.

Preferred as the material for the core 1 is a heavy metal fluorideglass, which in contrast to conventional silicate glass used for fibers,has crystal-like properties. The jacket 2 preferably also consists of aheavy metal fluoride glass, which however is doped with a dopant capableof scintillation. The preferred dopants are rare earth metals,particularly Ce, Nd, Pr, Er, Tm. Since heavy metal fluoride glass has ahigh density, an adequately large stopping power for γ-rays can beachieved; i.e. an optical waveguide constructed of this material issuitable for detecting not only low-energy radiation, but alsohigh-energy radiation such as γ-rays, for which reason it is preferredfor use in accordance with the invention.

Optically active centers of the pumped core material are schematicallyshown inside the fiber core 1 by means of small circles.

To illustrate the method of operation of the device in accordance withthe invention, FIG. 1 shows the path 4 of an ionizing particle or agamma-quantum that penetrates the optical fiber amplifier and generatesscintillation light by interacting with the dopant in the jacket 2, asshown in FIG. 1 at the location 5 of the jacket 2, from whichscintillation light is isotopically emitted. A part of the scintillationlight and/or the photons from interaction point 5 enters the fiber coreand is multiplied through the optical amplification process that takesplace there (assuming suitable frequency). In particular, the pumpinglight injected into the core 1 creates a population inversion there; thephotons radiated from scintillation which likewise enter the core 1trigger stimulated emission from the optically active centers and arethereby amplified within the core. They are coupled out of the core 1 ata suitable point for further processing.

Materials considered for the jacket 2 also in principle include suitablescintillating plastics, which are is extensively described in thescientific literature. Plastic material of this type finds broadapplication especially from high-energy physics to medical applications.A disadvantage of using scintillating plastics is that the Comptoneffect dominates in interactions with γ- or X-rays: in other words, theenergy of the gamma-quantum or X-ray quantum is only partially absorbedand the direction of the incident gamma quantum radiation is changed. Afurther disadvantage of this plastic material is its low averageabsorption (stopping power) for the incident radiation resulting fromthe low density of this material, as a result of which the efficiencyfor photon generation is poor. Lastly, this material has high internaldamping, as a result of which the generated scintillation light can onlybe transmitted over short distances. These disadvantages ofscintillating plastic are partially compensated for in the novelapplication of an optical fiber amplifier by the optical amplification,for which reason it can in principle be considered for use with theradiation detector in accordance with the invention.

Alternatively, a plastic fiber core doped with dye molecules that issurrounded by a scintillating jacket can serve as an optical amplifier.

The length of the fiber 1, 2 depends on the purpose of the applicationand is preferably between 5 mm and 5 m.

An advantage of the optically pumped optical waveguide 1, 2 embodied asoptical fibers lies in the high optical amplification that can beachieved, in the extremely compact construction which also permits usein arrangements that are not accessible by conventional detectors, andin the economical manufacturability.

However the invention is not limited to optical fibers. Rather, crystalsor planar optical waveguides manufactured from a material suitable foroptical amplification may also be considered. Finally, a number of suchdetecting elements or fibers can be combined.

A second embodiment of the detecting element of the device in accordancewith the invention is shown in FIG. 2. This embodiment differs from thefirst embodiment shown in FIG. 1 through the use of a double jacket(double cladding) 2 a, 2 b. The construction of the inner jacket 2 acorresponds to the construction of the jacket 2 of the embodiment inFIG. 1, and hence consists of a scintillating fiber material while theouter fiber jacket 2 a can consist of a conventional non-scintillatingfiber material with an index of refraction differing from that of theinner fiber jacket 2 b in such a way that light generated byscintillation in the inner fiber jacket 2 b is reflected at the boundarylayer between fiber jacket 2 a and fiber jacket 2 b. The advantage ofthis measure is that this reflected light, which is not available forthe amplification process in the embodiment in accordance with FIG. 1,is likewise fed into the amplification process.

FIG. 3 shows a third embodiment of the fiber-shaped detection material,which differs from the embodiment in FIG. 2 in that the pumping light isnot coupled into the fiber core 1, but rather into the inner fiberjacket 2 a. The advantage of this embodiment resides in a more favorableguiding of the pumping light as compared to the previous embodiments.Moreover, the optical fiber has as its outermost layer an opaque fibersheath 2 c, which prevents optical crosstalk with the neighboring fibers(optical isolation).

FIG. 4 shows a fourth embodiment of the detecting element of theradiation detector in accordance with the invention. The opticallyactive amplifier section in this embodiment is [formed] by an inorganicscintillating crystal (such as BGO) that is doped with laser-active rareearth metals. Thus the crystal simulaneously constitutes an active lasermedium and a scintillation medium. Used as an example is a crystal (suchas Nd—BGO) doped with rare earth metal ions. The BGO crystal 20, whichin the embodiment shown has the shape of a rectangular prism, has asimilar structure as in FIG. 3. The outermost opaque layer 23 providesoptical isolation from the neighboring element. The layers 21 and 22correspond to the inner (2 a) and outer (2 b) jacket material of FIG. 3.They serve as an optical transport element to couple pumping light intothe BGO crystal. The jacket material can consist of transparentplastics. Pumping light is coupled into layers 21 and 22 as shown byarrows 24 and 25 in order to pump the BGO crystal and thereby amplifyscintillation light generated by an incident light quantum, for examplea gamma-quantum, in the BGO crystal at position 26 in the crystalmaterial. The optically active centers are once again indicated withcircles 27. An advantage of this embodiment of the detecting element isthat costly photomultipliers can be dispensed with. Instead, inexpensivePIN or avalanche diodes can be used due to the preamplification in theoptical amplifier section.

FIG. 5 shows a preferred application of the radiation detector inaccordance with the invention with the embodiments of FIGS. 1 through 3in the shape of an optical fiber amplifier for detecting particles.Accordingly the fiber 1, 2 passes through the center of an elongatedcontainer 30 with an inlet 31 and an outlet 32 for a carrier fluid 33which flows around the fiber 1, 2 and contains radioactively markedmolecules 35 or, for example, marked cells 35, marked bacteria 35, ormarked viruses 35, that emit β-particles 34. The β-particles can nowpenetrate the fiber jacket 2 of scintillating material and producescintillation light, which is amplified by the optical fiber amplifierin accordance with the invention as described above. The first advantageof the device in FIG. 5 is that the emitted β-particles are located inthe immediate vicinity of the fiber amplifier. This is important becauseβ-particles have only a short range (a few millimeters). The secondadvantage of the device is that the tubular structure can have anydesired length so that the detection surface becomes large in relationto the fluid volume and the sensitivity increases. The third advantageof the device is that an interaction in the fiber core can be spatiallyassociated with the volume element. This is accomplished by measuringand comparing the amplified light exiting the fiber core 1 to the rightand to the left. This results in the opportunity to sort such things asmolecules, cells, bacteria or viruses. The fourth advantage is that thedevice can be continuously operated as a flow-through detector. Thispermits the monitoring of minute quantities of radioactive beta rays,for example in waste water.

While FIGS. 1 through 5 showed detection devices for radiation, FIG. 6shows an example of a biosensor for single molecule detection whichmakes it possible to detect small quantities of fluorescence-markedsubstances in fluids or in living organisms. Examples offluorescence-marked substances can be medicines or macromolecules suchas proteins. Moreover, fluorescence-marked cells, bacteria and virusescan be detected and quantified. Fluorescence light can be measured influids in vitro or in vivo in living organisms.

FIG. 6 shows an optical fiber that is characterized by a core 51 throughwhich the light 52 is coupled for fluorescence excitation, but whichdoes not serve as an optical amplifier section as previously described.The optical amplifier section here is located in the inner jacketsection 47. The outer jacket section 48 and the inner jacket section 47constitute the previously described optical waveguide. The outer layer49 provides mechanical protection for the fiber, is opaque, and preventsthe penetration of interfering light. In contrast to the previousexamples 1-5, in which the photons were generated within the sensorsection, the photons here are generated in the immediate vicinity of thesensor section. The sensor section serves to collect, amplify andtransport the fluorescence light. One end of the fiber is located, forexample, in a fluid (water, blood, organic solvent, etc. 41) or in a gel41 or sol (e.g. cytosol of cells 41), in which are located thefluorescence-marked substances 42 that are to be detected. In medium 41,into which the fiber extends, a spatially defined light cone 43 isformed by the fluorescence excitation light 52. When fluorescence-markedsubstances 42 enter this light cone 43 through diffusion or convection,the fluorescence-marked substance 42 is brought into an excited state 44and emits fluorescence light 45. A portion of the fluorescence light 45enters the interior of the fluorescence sensor. The material of theinner jacket functions once again as an optical fiber amplifier, and isactivated by pumping light 53. When a photon 45 now strikes an opticallyactive center 46, the net result is optoelectronic avalancheamplification and the amplified fluorescence light 50 exits at the otherend of the fiber. Optoelectronic conversion can preferably beaccomplished with a PIN or avalanche diode.

What is claimed is:
 1. A method for the detection of incident-radiation, comprising converting said incident radiation in a sensorsection of an optical waveguide into a radiation output comprisingphotons in the UV, visible, or IR portions of the electromagneticspectrum by interacting with a photon-emitting material included in aglassy material having crystal-like properties and a sufficient densityto stop γ-radiation, and amplifying said radiation output in anoptically pumped amplifier section of said optical waveguide, theamplifier section comprising a glassy material having crystal-likecharacteristics and a sufficient density to stop γ-radiation.
 2. Amethod according to claim 1, wherein the amplifier section is opticallypumped by pulsed light.
 3. An optical waveguide device for the detectionof incident radiation, comprising at least one detection elementincluding (i) a sensor for converting the incident radiation into aradiation output comprising photons in the UV, visible, or IR portionsof the electromagnetic spectrum, the sensor comprising a glassy materialhaving crystal-like characteristics and a sufficient density to stopγ-radiation, the sensor further comprising a photon-emitting material;and (ii) an optical amplifier that receives said radiation output fromthe sensor section, amplifies the radiation output and transmits it forfurther processing, said optical amplifier comprising a glassy materialhaving crystal-like characteristics and a sufficient density to stopγ-radiation that is at least partially optically pumped foramplification of said radiation output.
 4. A device according to claim3, wherein the glassy material having crystal-like characteristics and asufficient density to stop γ-radiation is a heavy metal fluoride glass.5. A device according to claim 3, wherein the photon-emitting materialis at least one atom from the lanthanide group.
 6. A device according toclaim 4, wherein the glassy material having crystal-like characteristicsand a sufficient density to stop γ-radiation of the optical amplifierincludes at least one inorganic crystal component selected from thegroup consisting of BGO, CeF, BaF₂.
 7. A device according to claim 3,wherein the incident radiation is selected from the group consisting ofX-rays, β-radiation, gamma rays, ionizing radiation, fluorescence andlow-level light.
 8. A device according to claim 7, wherein saidamplifier section is surrounded by said sensor.
 9. A device according toclaim 7, wherein a pumping light source is coupled to the core of theoptical waveguide.
 10. A device according to claim 8, wherein theoptical waveguide device is combined with an instrument selected fromthe group consisting of a NMR device, a PET system, an X-ray imagingdevice, biosensor, and radioimmunoassay.
 11. A device according to claim3, wherein a pumping light source is coupled to the optical waveguide,said pumping light source generating at least one of (a) continuouspumping light, (b) pulsed pumping light, (c) one or more wavelengths oflight, and (d) infrared light.
 12. A device according to claim 3,wherein the optical waveguide comprises a columnar microstructure.
 13. Adevice according to claim 3, wherein the optical waveguide comprises aplanar waveguide.
 14. A device according to claim 3, wherein the opticalamplifier is coupled to an optoelectronic converter.
 15. A deviceaccording to claim 3, wherein said sensor comprises wavelength shiftersfor photonic conversion of the radiation output to higher wavelengththan would be generated in the absence of said wavelength shifters. 16.A device according to claim 3, wherein said sensor has an elongate shapefor directional selection of incident γ-radiation.
 17. A process todetermine γ rays wherein the rays are transformed into photons in theUV, visible or IR range of the electromagnetic spectrum in a sensor inan optical waveguide, wherein the γ rays are transformed by the sensorinto photons by interacting with a photon-emitting material included ina heavy metal fluoride glassy material, the photons are taken by anoptically pumped amplifier component and transmitted in an amplifiedstate, the amplifier component comprising a heavy metal fluoride glassymaterial.
 18. A process according to claim 17 wherein the amplifiercomponent is optically pumped with pulsed light.
 19. An opticalwaveguide device to determine γ rays with at least one sensor andoptical amplifier section, the amplifier section takes the lighttransformed by the sensor and transmits it to be further processed in anamplified state, the sensor comprises a heavy metal fluoride glassymaterial having a sufficient density to stop γ-radiation, the sensorfurther comprising a photon-emitting material to transform γ rays intophotons in the UV, visible or IR range of the electromagnetic spectrum,and the amplifier section comprises a heavy metal fluoride glassymaterial having a sufficient density to stop γ-radiation.
 20. A processto determine β-radiation wherein the β-radiation is transformed intophotons in the UV, visible or IR range of the electromagnetic spectrumin a sensor of an optical waveguide, wherein the β-radiation istransformed by the sensor into photons by interacting with aphoton-emitting material included in a non-silicate glassy materialhaving crystal-like properties and a sufficient density to stopγ-radiation, the photons are taken by an optically pumped amplifiercomponent that is also in the optical waveguide and transmitted in anamplified state, the amplifier component comprising a non-silicateglassy material having crystal-like characteristics and a sufficientdensity to stop γ-radiation.
 21. A process according to claim 20 whereinthe amplifier part is optically pumped by pulsed light.
 22. A processaccording to claim 20 wherein a fluid that contains β-radiation at leastpartially circulates around the light guide.
 23. A device to determineincident radiation with at least one sensor and optical amplifier, theoptical amplifier takes the light transformed by the sensor andtransmits it to be further processed and amplified, the sensorcomprising a non-silicate glassy material having crystal-likecharacteristics and a sufficient density to stop γ-radiation, the sensorfurther comprising a photon-emitting material; and the optical amplifiercomprising a non-silicate glassy material having crystal-likecharacteristics and a sufficient density to stop γ-radiation.
 24. Adevice according to claim 23 wherein the light guide passes through acontainer with an inlet and an outlet for a fluid that circulates aroundthe light guide and contains or can contain rays.
 25. A process todetect fluorescent light where fluorescent light enters one end of thelight guide in a sensor part that is in an optical light guide, and thelight absorbed by the sensor part is transmitted in an amplified statein an optically pumped amplifier that is also in the optical lightguide, the sensor comprising a glassy material having crystal-likecharacteristics and a sufficient density to stop γ-radiation, the sensorfurther comprising a photon-emitting material; and the optical amplifiercomprising a glassy material having crystal-like characteristics and asufficient density to stop γ-radiation.
 26. A device according to claim25, wherein light for fluorescence excitation is coupled into theoptical light guide, and the light forms a spatially defined light coneat one end of the light guide.
 27. A detector for detection of incidentradiation, comprising a sensor comprising a glassy material havingcrystal-like characteristics and a sufficient density to stopγ-radiation and a photon-emitting material; and an optical amplifiercomprising a glassy material having crystal-like caharacteristics andsufficient density to stopγ-radiation.